Device for mixing and proportioning liquids

ABSTRACT

An apparatus for mixing and proportioning liquids includes a plurality of tanks for containing liquids to be mixed together. Each of the tanks has a bucket carrying assembly disposed therein, each such assembly being arranged for rotation to cause the buckets to successively enter into and emerge from the liquid contained in their respectively associated tank. The buckets are provided with means whereby each bucket is completely filled during each rotation cycle of each assembly. The buckets are also provided with means to effect discharge of the content of the buckets at a discharge region and a mixing device is provided to receive the discharged liquids and mix them together. The liquid capacities for buckets of each assembly are preselected to permit the several liquids to be mixed together in the desired proportions.

United States Patent Inventors Colin Kenneth Glenn Fraser;

Ernest Favreau; Willis Paul March, Vancouver, British Columbia, CanadaAppl. No. 854,888

Filed Sept. 3, 1969 Patented May 25, 1971 Assignee Kaydon TechnicalEnterprises, Ltd.

Vancouver, Canada Priority Sept. 5, 1968 Canada 029,275

DEVICE FOR MIXING AND PROPORTIONING LIQUIDS 23 Claims, 8 Drawing Figs.

US. Cl 259/4, 222/139, 222/318, 222/367, 259/18, 415/6 Int. Cl 801i15/04, GOSd 1 1/02 Field of Search 259/4, 18;

[56] References Cited UNITED STATES PATENTS 1,190,721 7/1916 Campbell415/6X 1,372,768 3/1921 Mott 222/367X Primary ExaminerWilliam T. PriceAttorney-Cushman, Darby and Cushman ABSTRACT: An apparatus for mixingand proportioning liquids includes a plurality of tanks for containingliquids to be mixed together. Each of the tanks has a bucket carryingassembly disposed therein, each such assembly being arranged forrotation to cause the buckets to successively enter into and emerge fromthe liquid contained in their respectively associated tank. The bucketsare provided with means whereby each bucket is completely filled duringeach rotation cycle of each assembly. The buckets are also provided withmeans to effect discharge of the content of the buckets at a dischargeregion and a mixing device is provided to receive the discharged liquidsand mix them together. The liquid capacities for buckets of eachassembly are preselected to permit the several liquids to be mixedtogether in the desired proportions.

Patented May 25, 1971 5 Sheets-Sheet 2 Caz/M Kim 57W 415v Frflss/rPatented May 25, 1971 3,530,545

5 Sheets-Sheet 5 DEVICE FOR MIXING AND PROPORTIONING LIQUIDS Thisinvention relates to a device for mixing liquids together and accuratelyproportioning said liquids relative to one another thereby to provide awell mixed solution of predetermined concentration.

While the principles of the present invention are applicable to manydifferent situations wherein a chemical solution of predeterminedstrength is required, the present invention is particularly well suitedfor use in central supply units for servicing artificial kidneys.

A major problem in servicing artificial kidney units has been therequirement for a constant supply of dialysate, a salt and watersolution, at a constant predetermined concentration. If the requiredconcentration, i.e. 34 parts water to one part chemical concentrate, isnot maintained, serious damage, or even the death of the patient canresult. The present invention substantially eliminates the difficultiesinherent in the earlier forms of dialysate supply units and greatlyfacilitates the provision of a continuous supply of dialysate at anexact, predetermined concentration.

The present invention, accordingly, provides an apparatus for mixing andproportioning liquids. The apparatus includes a plurality of tanksadapted to contain the liquids to be mixed together. Each of the tankshas an assembly at least partially disposed therein and carrying aplurality of buckets having predetermined capacities chosen inaccordance with the required liquid proportions. These assemblies areconstructed such that when the assemblies are driven, the bucketssuccessively enter into and emerge from the liquids contained in theirrespectively associated tanks. The buckets are provided with means topermit them to completely fill while they are in the liquids and tocompletely discharge after their emergence therefrom. The dischargingliquids are directed into a mixing device arranged to thoroughly mix theseveral liquids together. The liquid capacities of the buckets of eachassembly are selected relative to the liquid capacities of the bucketsof each other assembly to provide the desired proportioning of theliquids to be mixed. In the example to be described hereinafter, twobucket carrying assemblies are provided, with the volume of each bucketof a first one of the assemblies being a predetermined fraction of thevolume of each bucket of the second assembly. In the case of dialysatepreparation, the volume ratio between the two sets of buckets is 34:1.

The present invention includes many other important features, fulldescriptions of which are given below. For definitions of the presentinvention reference should be had to the appended claims.

In the drawings which illustrate an embodiment of the invention:

FIG. I is a perspective view illustrating the mixing and proportioningunit of the present invention mounted in a cabinet;

FIG. 2 is a perspective view of the mixing and proportioning unit withcertain portions of the assembly being cut away to show the internalstructure;

FIG. 3 is a perspective view illustrating the mixing trough and mixinghopper subassembly;

FIGS. 4 and 5 are plan and elevation views respectively of one of thebucket wheel assemblies;

FIGS. 6 and 7 are elevation and plan views respectively of one of thebuckets;

FIG. 8 is a schematic diagram of the electrical circuit for the bucketwheel drive.

FIG. I shows the supply unit mounted in a cabinet 10 of size sufficientto accommodate the mixing and proportioning unit 12 as well as the manyelectrical controls, pumps, fluid supply inlets and outlets and the likenormally associated with a device of this nature. Cabinet I0 includes alid 14 hinged to the remainder of the cabinet. Lid 14 preferably isprovided with a transparent top I6 to permit the mixing andproportioning unit to be observed without the need of swinging lid 14upwardly, thus reducing the possibility of contamination of the liquidsbeing mixed.

The mixing and proportioning unit 12 includes three separate tankspositioned in side-by-side relation. The center tank 18 is called themixing tank while the remaining tanks 20 and 22 which flank the mixingtank 18 are referred to respectively as the concentrate tank and thewater tank. As may be seen in FIG. 2 the concentrate tank 20 may be ofsomewhat smaller volume than the remaining two tanks.

Extending transversely of the three tanks 18, 20 and 22 at a levelslightly below the level of the upper sidewall portions of the tanks isa shaft 24 mounted for rotation in suitable bearings (not shown).Secured to the shaft 24 in spaced apart relation are the bucket wheelassemblies referred to generally as 26 and 28. Bucket wheel assembly 26is generally of smaller dimensions than the assembly 28 and ispositioned so that its lower half is disposed in the concentrate tank20, while the large bucket wheel assembly 28 is disposed with its lowerhalf generally in water tank 22.

The several components of the bucket wheel assemblies may convenientlybe made from a clear, transparent plastic, nontoxic and nonreactive withthe liquids being handled. FIGS. 1 and 2, in particular, show theseveral components of these assemblies as they would appear when thetransparent plastic material is used.

Since the two bucket wheel assemblies are of the same generalconstruction, the bucket wheel assembly 26 only will be described indetail, particular reference being had to FIGS. 4 and 5. Bucket wheel 26includes a generally circular disc 30 having a cylindrical hub 32centrally secured thereto and projecting outwardly from one face of disc30. Secured to the disc 30 on the face opposite the face to which hub 32is secured are a plurality of concentrate buckets 34, in this case fivein number. The buckets 34 are spaced apart a uniform angular amount, inthis case 72, and are disposed a uniform distance from the rotation axisof disc 30 defined by shaft 24.

A typical bucket is illustrated in detail in FIGS. 6 and 7. Each bucket34 includes a generally hollow body 36 of circular or other suitablecross section, closed at its base and preferably having a domed top 38.A fill spout 40 is positioned closely adjacent the highest point of thedomed top to prevent air entrapment within bucket 34 during fillingwhile a pour spout 42 is positioned well over towards the sidewall ofthe bucket body to permit the bucket 34 to empty completely through thepour spout as the bucket assumes an inverted position during rotation ofthe disc 30. Both the fill and pour spouts are parallel to the medialaxis of the bucket body 36.

Buckets 34 are secured to the face of disc 30 via brackets 44 bysuitable securing means and in such a fashion that the medial axis ofeach bucket is disposed at an angle to a radius of the disc 30 passingadjacent a central point of the bucket. In the case of the bucket wheelassembly 26 this angle is conveniently about 45 while with the somewhatlarger bucket wheel assembly 28 the angle is about 55". These angles maybe varied considerably, but as will be seen hereinafter, the liquidlevels which must be maintained in the tanks 20 and 22 must be variedaccordingly if proper filling and levelling of buckets 34, 34 is to takeplace. It will be appreciated that such angle is measured in a planeparallel to the plane of disc 30 and that the pour and fill spouts 42and 40 face generally in the direction of rotation of disc 30 indicatedby the arrow R, with the fill ports 40 being located generally radiallyoutwardly of the pour spouts 42 all as shown in FIG. 4.

The pour spout 42 of each bucket is connected to an elongated hose 46which extends from the pour spout in a curved path directed bothinwardly toward the rotation axis of disc 30 and angularly about thelatter, in this case about 72, in the direction of rotation of disc 30.Each hose 46 then passes through an associated passageway 48 whichextends through the disc 30 and the hub 32, in such a manner that theexit end 50 of each hose 46 projects a short distance outwardly of theface 52 of the free outer end of hub 32. Each passageway 48 extendsthrough hub 32 at an oblique angle with respect to the rotation axis ofthe latter whereby the hose 46 passing therethrough effectively passesstill further around said rotation axis in the direction of rotation ofthe disc. By virtue of the path taken by each hose 4% from the pourspout of the bucket associated therewith through to its exit end 30,such exitend is displaced approximately l80 about the rotation axis ofthe assembly from the pour spout of the bucket in the direction ofrotation of the bucket wheel assembly. This configuration, as will beseen later, facilitates pouring of the buckets 34 as the bucket wheelassembly rotates.

Bucket wheel assembly 28 is of the same general construction as bucketwheel assembly 26 and except for its dimensions is a mirror image of thelatter. The two assemblies 26 and 28 are mounted with their respectivehubs 32, 32' in spaced, confronting relation with the exit ends 50 ofthe pour hoses 46 of bucket wheel assembly 26 projecting generallytowards the exit ends 50' of the pour hoses associated with bucket wheelassembly 23. As can be seen from FIGS. I and 2, the hubs 32, 32' andtheir associated hose exit ends 50 project a short distance inwardly ofmixing tank 113 through cutouts in the opposing sidewalls of the latter.The buckets 3d of assembly 26 and the buckets 34! of assembly 28 occupyangular positions about shaft 24 which correspond with one anotherthereby ensuring that each bucket 34 discharges simultaneously with itscorresponding bucket 36 on the opposing bucket wheel assembly.

The volume of each bucket 34 is carefully chosen relative to the volumeof each bucket 34'. In the case of dialysate preparation, the buckets34"which dip into water tank 22 each have a volume 34 times as great asthe volume of each buckets 34 which handle the chemical concentrate.This provides, as will be seen later, a solution having 34 parts waterto one part concentrate. Accurate and complete filling of each bucket isassured by virtue of the relatively small fill ports 40, 40 on thebuckets, which permit accurate calibration of the volume of each bucket.In addition, the levels of the concentrate in tank 20 and the levels ofthe water in tank 22 are maintained between the optimum maximum andminimum values required to provide accurate bucket levelling. The levelin concentrate tank 20 is maintained by float valve 54 which isconnected to a supply of chemical concentrate at room temperature, whilethe level in water tank 22 is maintained by float valve 54', the latterbeing connected to a supply of sterile water heated to about 100 F. Theoptimum liquid levels to be maintained in the concentrate tank 20 andthe water tank 22 are dependent somewhat upon the previously mentionedangles which the medial axes of the buckets 34, 34' make with radiallines on disc 30 passing adjacent central points of the buckets. Theliquid level in each tank must be maintained at a level which willpermit each bucket 36, 34' to occupy a true upright vertical positionwith at least the upper portion of the fill spout 443 above the liquidsurface as each bucket emerges from the liquid during rotation of thebucket wheel assemblies in the direction given by the arrows R. If theliquid level is too high, the buckets will have taken an inclinedposition by the time their fill spouts clear the liquid surface and thebucket will not contain the amount for which it has been calibrated; ifthe liquid level is too low, the buckets will not have an opportunity tofill properly before they emerge from the liquid.

As mentioned previously, the bucket wheel assemblies 26, 2b are arrangedsuch that their respective hubs 32, 32 face towards each other with theexit ends 50, 50) of pour hoses as 46' also projecting generally towardseach other. In order to receive the contents of the buckets 343, 34' asthey discharge their contents through pour hoses 46, as, there isdisposed within the mixing tank M, a mixer generally designated 56 asseen in FIGS. 2 and 3. Mixer 56 includes an elongated trough having itslongitudinal axis disposed parallel to the axis of shaft 24 withopposing ends of trough 58 having cutout portions 60 which permit thehubs 32, 32' of the bucket wheel assemblies to extend a short distanceover and into trough 53 from opposing ends of the latter. The bottomfloor portions 59 of trough 53 slope downwardly towards the center ofthe latter and lead into and are secured to the open upper end of a ho]-low cylinder 64) which extends downwardly towards the floor of themixing tank 18. Secured to the lower end of cylinder 60 is a generallyconical portion 62 having a plurality of small openings 64 therein. Thelowermost end of conical portion 62 has an opening therein through whichthe end portion of a return pipe 66 projects, the latter being alignedwith the axis of cylinder 60.

The floor of mixing tank 18 has a mixture outlet 68 therein connected tothe inlet of a positive displacement pump 70. The outlet of pump 70 isconnected to a manifold 71 which in turn supplies a number of artificialkidney units, one of which is designated as 73, with the mixture fromtank 18. Since the artificial kidney units use only a portion of themixture supplied thereto from the manifold, there is a substantialreturn flow through manifold return 72, such return flow passingupwardly through return pipe 66 thereby to effect proper mixing of thefluids supplied from the bucket wheel assemblies 26 and 28 as will bemore fully described hereinafter.

The liquid level of the mixture within mixing tank 18 is held well belowthe edges of trough 58 of mixer 56 thus preventing liquid from themixingtank 18 from entering the upper end of the mixer. This liquid level iscontrolled by means of a diaphragm switch 74 positioned on the floor ofmixing tank 118. Diaphragm switch 74 is sensitive to the head" of liquidin tank 18 and responds thereto to effect make and break of the circuitshown in FIG. 8. The circuit of FIG. 8 is connected across a supplysource S" and includes on-off switch 76, the windings of a gearmotor 78,and a limit switch connected in parallel with diaphragm switch 74. Thegearmotor 78 is connected by suitable chain and sprocket means 82 toeffect rotation of shaft 24 and the bucket wheel assemblies 26, 28 at aslow, uniform rate of speed (in the present case about 2 rpm). A cam 84which rotates with gearmotor 78 controls the opening and closing ofswitch 80 and since the latter is connected in parallel with diaphragmswitch 74 it will be appreciated that both switches must be open" beforethe supply to the gearmotor 78 is cut off. In operation, once the liquidlevel in tank 1% exceeds the desired level, the diaphragm switch opens;however the gearmotor 78 continues to drive the bucket wheel assemblies26 and 28 until the latter reach an angular position wherein oneconcentrate bucket 34 and one water bucket 34 have just finisheddischarging their contents, while the following two buckets have not yetstarted to discharge. At this point the follower lever 85 on switch bl)drops into a cutaway portion on the surface of the cam 84 thus cuttingoff the power to geannotor 73. In this way there is never a partialdischarge of either water or concentrate into the mixture tank with theresult being that the concentration of the mixture remains constant. Asthe mixture is pumped out of tank M by pump 70, the level of tank I8drops and the diaphragm switch closes thus supplying power to thegearmotor 73 to again drive the bucket wheel assemblies in rotation.

It will be realized that suitable heater means should be provided tomaintain the temperature of the mixture in the tank 18 at a propertemperature. In the case of dialysate preparation, this temperature ismaintained at 37 C. in addition, suitable controls must be provided tomaintain the output pressure of pump 70 at the correct value. Othercontrol and alarm systems for indicating under or over temperatureconditions in any of tanks I8, 20 and 22, improper pump outputpressures, or variations in the concentration of the mixture in tank 18will be necessary when the device of the present invention is used as adialysate supply unit. However, since such control and alarm systems donot comprise a part of the present invention they will not be furtherdescribed here.

The operation of the device will now be described with particularreference being had to FIG. 2 of the drawings. As the bucket wheelassemblies 25 and 2% rotate in the direction given by the arrows R thebuckets 34, 3d enter the fluids in the respective tanks 20 and 22 in aninverted position. Liquid enters the fill ports M9, 40 of the bucketswith air being exhausted through the pouring ports d2, 42' and theirassociated pouring hoses 46, M. The buckets continue to fill as rotationcontinues and they are completely full prior to their emergence from theliquids in their associated tanks. As the buckets emerge, they areactually over full" as liquid has filled a portion of their associatedpouring hoses 46, 46. At this point each emerging bucket is in a truevertical position allowing some of the liquid contained in the pouringports 42, 42' and pour hoses 46, 46 to drain off outwardly through thefill ports 40, 40'. This action takes place during continuous rotationof the bucket wheel assemblies 26, 28 at the rate of 2 r.p.m. At thisinstant of time the liquid levels in each of the two emerging bucketsare in exact correspondence with the uppermost extremities of the bucketfill ports 40, 40' with the result being that the buckets 34, 34' underconsideration hold the exact amounts of liquid for which they have beencalibrated.

As rotation of the bucket wheel assemblies continues,.the contents ofthe two buckets under consideration discharge through their associatedpour hoses into the mixer 56. By virtue of the previously mentionedconfiguration of the pour hoses, the discharging fluid is carriedoutwardly through the hubs 32, 32' and makes its exit from the exit ends50 which project outwardly of the ends of the hubs. Due to the fact thateach pour hose exit end 50 is displaced some 180 about the axis ofrotation from the bucket with which it is associated, the hose exit end50 through which fluid is discharging is at a lower elevation than theremaining exit ends 50 with the result being that fluid is dischargedwell down into the trough of the mixer 56 and, in addition, there is nochance that some fluid discharging from one exit end 50 will find itsway back into an adjacent one of the exit ends 50 and thence work itsway back into an associated bucket hence creating inaccuracies in theproportioning of the two liquids. It will, of course, be appreciatedthat during the above described sequence, the remaining buckets of theassemblies 26 and 28 are in various stages of filling, pouring, etc.,and that the sequence described is repeated over and over as long asrotation of assemblies 26, 28 is continued.

The two liquids discharging from the bucket wheel assemblies pass intothe trough 58 of mixer 56 and thence flow downwardly into the verticallydisposed cylinder 60 where the two liquids encounter the return flowfrom manifold 71 passing upwardly through the return pipe'66. Due to thecountercurrents and turbulence thus createdwithin cylinder 60, theliquids flowing from the two bucket wheel assemblies are well mixed withthe return fluid.

As the buckets continue to pour their contents into mixer 56, the liquidlevel in the latter tends to rise slightly above the liquid level in themixing tank 18; however; this causes mixed fluid to escape through theapertures 64 in the conical section 62 at the lower end of mixer 56 thusmaintaining the liquid heads, or levels, in the mixer 56 and in themixer tank 18, substantially equal to one another. The passage of theliquid through the numerous small apertures 64, such liquid alreadyhaving been thoroughly agitated withinthe cylinder portion 60 of mixer56, completes the mixing process. The mixed liquids are pumped out ofmixing tank 18 by the pump 70 with the level in tank 18 being maintainedapproximately constant as described previously.

Although the mixing and proportioning unit of the present invention isespecially adapted for use in apparatus for supplying dialysate to aplurality of artificialkidney units, it will be realized that theapparatus of the present invention is useful in other areas as wellwherein thorough mixing and proportioning of one liquid relative toanother liquid is desired.

I claim:

1. A device for mixing and proportioning fluids comprising:

a. first and second tanks for containing first and second liquidsrespectively,

b. first and second rotatably mounted bucket wheel assemblies associatedwith said first and second tanks respectivel c. the first and secondbucket wheel assemblies each having thereon a plurality of buckets withthe liquid capacity of each of the buckets of the first bucket wheelassembly being in predetermined relation to the liquid capacity of eachof the buckets of the second bucket wheel assembly,

(1. said buckets being mounted on their respective bucket wheelassemblies and the bucket wheel assemblies being so associated with thefirst and second tanks that said buckets of the first bucket wheelassembly sequentially enter into and emerge from the liquid contained inthe first tank while the buckets of the second bucket wheel assemblysequentially enter into and emerge from the liquid contained in thesecond tank during rotation of the two bucket wheel assemblies.

e. fill means on each bucket arranged to permit complete filling of eachbucket between the times the buckets sequentially enter into and emergefrom the liquids contained in the first'and second tanks,

f. discharge means associated with each bucket to permit the contents ofeach of the latter to discharge after emergence of each bucket from theliquids contained in the first and second tanks,

g. mixer means adapted to receive the proportioned, discharged liquidspassing through said discharge means, said mixer means including meansarranged to create turbulence therein to effect mixing of the liquidsfrom said first and second tanks,

h. and discharge means associated with said mixer means to permitoutflow' of the proportioned mixed liquid therefrom.

2. The device according to claim 1 wherein the buckets of the firstbucket wheel assembly are mounted relative to the buckets of the secondbucket wheel assembly as to permit discharge of each of the firstmentioned buckets substantially simultaneously with discharge of each ofthe second mentioned buckets.

3. The device according to claim 1 further including a third tankadapted to contain a mixture of said first and second liquids, saidmixer means being disposed relative to said third tank so that thelatter may receive the mixed liquids from the discharge means of saidmixer means, and outlet means in said third tank.

4. The device according to claim 1 wherein said bucket wheel assembliesare mounted for rotation about a common axis and wherein each bucketwheel assembly includes means supporting said buckets in spaced arrayabout the rotation axis of the bucket wheels, said discharge meansincluding fluid conductors connected to each bucket and extendingtherefrom generally radially inwardly towards said rotation axis suchthat the exit end portions of the fluid conductors are spaced about therotation axis, said mixer means including means positioned beneath saidexit end portions to receive discharge liquid therefrom.

5. The device according to claim 3 wherein the outlet means of saidthird tank is adapted to be connected to a user of the proportioned,mixed, liquids, and wherein the means for creating turbulence within themixer include a conduit connected to return unused liquid from said userto said mixer to set up a liquid flow opposing the flow set up in saidmixer by the liquids discharged from said buckets thereby creatingturbulence to ensure proper mixing of the return liquid with thedischarged liquids.

6. The device according to claim 5 wherein the discharge meansassociated with the mixer includes a plurality of apertures in a lowerportion thereof to permit escape of the mixed liquids from the interiorof the mixer.

7. The device according to claim 3 wherein said bucket wheel assembliesare mounted for rotation about a common axis and wherein each bucketwheel assembly includes means supporting said buckets in spaced arrayabout the rotation axis of the bucket wheels, said discharge meansincluding-fluid conductors connected to each bucket and extendingtherefrom generally radially inwardly towards said rotation axis suchthat the exit end portions of the fluid conductors are spaced about therotation axis, said mixer means including means positioned beneath saidexit end portions to receive discharge liquid therefrom.

8. Apparatus for mixing and proportioning fluids comprising:

a. first and second containers for holding first and second liquidbodies respectively;

b. first and second assemblies supporting first and second sets ofspaced buckets respectively and arranged to guide said first and secondsets of buckets in first and second paths of travel respectively, saidfirst and second assemblies arranged such that when the apparatus is inuse, a portion of said first path of travel is adapted to pass throughthe first liquid body and a portion of the second path is adapted topass through the second liquid body;

c. means for driving the first and second sets of buckets in theirrespective paths of travel whereby they successively enter and emergefrom their respectively associated liquid bodies;

d. fill ports in each of said buckets to enable said buckets to fillwith said liquids during passage of the buckets through said liquids;

e. discharge means associated with each of said buckets arranged topermit escape of the contents of said buckets after emergence thereoffrom said first and second liquids,

. mixing means arranged to receive the liquids escaping from saidbuckets and adapted to mix the first and second liquids together,

g. the liquid capacity of each bucket of the first set being inpredetermined relation to the liquid capacity of each bucket of thesecond set whereby predetermined proportions of said liquids are mixedtogether in said mixing means.

9. Apparatus according to claim 8 wherein said first and secondassemblies support the first and second sets of buckets for movementincircular paths lying in spaced vertical planes.

10. Apparatus according to claim 9 wherein the buckets are so arrangedon said first and second assemblies that discharge of the contents ofsuccessive ones of the buckets of the first set occurs simultaneouslywith discharge of the contents of successive ones of the buckets of thesecond set.

ill. Apparatus for mixing and proportioning liquids comprising: aplurality of tanks for containing liquids to be mixed together; each ofthe tanks having at least partially disposed therein an assemblycarrying a plurality of buckets, said assemblies being adapted to rotateto cause said buckets to successively enter into and emerge from theliquids contained in their respectively associated tanks, means toeffect rotation of said assemblies, means associated with each bucket topermit filling of each of said buckets during each rotation cycle ofeach of the assemblies, means associated with each bucket to effectdischarge of the contents of the buckets at a discharge region, andmixing means adapted to receive the liquids discharged at the dischargeregion and adapted to mix the liquids together, the liquid capacities ofthe buckets of each assembly being preselected to permit a desiredproportioning of the several liquids relative to one another.

12. Apparatus according to claim H ll'wherein a mixing tank is providedwith said mixing means constructed to discharge the mixed liquids intosaid mixing tank, there being two tanks for containing liquids to bemixed together disposed in flanking relation to the mixing tank.

13. Apparatus according to claim 111 wherein each said assemblycomprises means supporting said plurality of buckets in a circular arrayfor rotation in a vertical plane, each of the assemblies being mountedfor rotation about a common axis, there being equal numbers of bucketson each assembly with said buckets mounted for substantiallysimultaneous discharge of their contents during rotation of saidassemblies.

14. Apparatus according to claim 13 wherein the means to effectdischarge of the buckets includes discharge conduits associated withrespective ones of said buckets and extending from each of the latterinwardly towards said common axis to exit end portions spaced around thelatter, such portions generally overlying said mixing means.

15. An apparatus according to claim 14 wherein said mixing meansgenerally includes an elongated trough defining said discharge regionunderlying said rotation axis and disposed to receive liquid dischargingfrom the exit end portions of said conduits, a chamber connected to saidtrough to receive liquids passing from said trough, and means forcreating turbulence within said chamber to create proper mixing of saidliquids.

16. Apparatus according to claim 15 wherein a mixing tank is provided toserve as a reservoir for the mixed, proportioned liquids and whereinsaid chamber has a plurality of apertures in a lower portion thereof topermit outflow of the mixed liquids into the mixing tank, said mixingtank having an outlet opening therein permitting the mixed, proportionedliquids to be supplied to a user.

17. Apparatus according to claim 16 including pump means connected tosaid outlet opening of the mixing tank adapted to supply the mixedliquids to said user, said pump having a capacity to supply the liquidat a rate greater than that demanded by said user, and a pipe connectedto return excess liquid from said user to said mixing tank, said pipebeing arranged to direct the return flow of excess liquid upwardly intosaid chamber of the mixing means thereby to provide said means forcreating turbulence within said chamber.

1%. Apparatus according to claim 13 including means for maintaining theupper surfaces of the liquids in said tanks at predetermined levels,said buckets being mounted on their associated assemblies in such manneras to permit the medial axis of each bucket to assume a true verticalposition after the filling means of each bucket rises above the liquidsurface during rotation of the assembly on which such bucket is mountedthereby permitting levelling of the contents of each bucket.

19. Apparatus according to claim 18 wherein each said assembly comprisesmeans supporting said plurality of buckets in a circular array forrotation in a vertical plane, each of the assemblies being mounted forrotation about a common axis, there being equal numbers of buckets oneach assembly with said buckets mounted for substantially simultaneousdischarge of their contents during rotation of said assemblies.

20. Apparatus according to claim i9 wherein the means to effectdischarge of the buckets includes discharge conduits associated withrespective ones of said buckets and extending from each of the latterinwardly towards said common axis to exit end portions spaced around thelatter, such portions generally overlying said mixing means.

21. Apparatus according to claim 20 wherein said mixing means generallyincludes an elongated trough defining said discharge region underlyingsaid rotation axis and disposed to receive liquid discharging from theexit end portions of said conduits, a chamber connected to said troughto receive liquids passing from said trough, and means for creatingturbulence within said chamber to create proper mixing of said liquids.

22. Apparatus according to claim 21 wherein a mixing tank is provided toserve as a reservoir for the mixed, proportioned liquids and whereinsaid chamber has a plurality of apertures in a lower portion thereof topermit outflow of the mixed liquids into the mixing tank, said mixingtank having an outlet opening therein permitting the mixed, proportionedliquids to be supplied to a user.

23. Apparatus according to claim 22 including pump means connected tosaid outlet opening of the mixing tank adapted to supply the mixedliquids to said user, said pump having a capacity to supply the liquidat a rate greater than that demanded by said user, and a pipe connectedto return excess liquid from said user to said mixing tank, said pipebeing arranged to direct the return flow of excess liquid upwardly intosaid chamber of the mixing means thereby to provide said means forcreating turbulence within said chamber.

1. A device for mixing and proportioning fluids comprising: a. first andsecond tanks for containing first and second liquids respectively, b.first and second rotatably mounted bucket wheel assemblies associatedwith said first and second tanks respectively. c. the first and secondbucket wheel assemblies each having thereon a plurality of buckets withthe liquid capacity of each of the buckets of the first bucket wheelassembly being in predetermined relation to the liquid capacity of eachof the buckets of the second bucket wheel assembly, d. said bucketsbeing mounted on their respective bucket wheel assemblies and the bucketwheel assemblies being so associated with the first and second tanksthat said buckets of the first bucket wheel assembly sequentially enterinto and emerge from the liquid contained in the first tank while thebuckets of the second bucket wheel assembly sequentially enter into andemerge from the liquid contained in the second tank during rotation ofthe two bucket wheel assemblies. e. fill means on each bucket arrangedto permit complete filling of each bucket between the times the bucketssequentially enter into and emerge from the liquids contained in thefirst and second tanks, f. discharge means associated with each bucketto permit the contents of each of the latter to discharge afteremergence of each bucket from the liQuids contained in the first andsecond tanks, g. mixer means adapted to receive the proportioned,discharged liquids passing through said discharge means, said mixermeans including means arranged to create turbulence therein to effectmixing of the liquids from said first and second tanks, h. and dischargemeans associated with said mixer means to permit outflow of theproportioned mixed liquid therefrom.
 2. The device according to claim 1wherein the buckets of the first bucket wheel assembly are mountedrelative to the buckets of the second bucket wheel assembly as to permitdischarge of each of the first mentioned buckets substantiallysimultaneously with discharge of each of the second mentioned buckets.3. The device according to claim 1 further including a third tankadapted to contain a mixture of said first and second liquids, saidmixer means being disposed relative to said third tank so that thelatter may receive the mixed liquids from the discharge means of saidmixer means, and outlet means in said third tank.
 4. The deviceaccording to claim 1 wherein said bucket wheel assemblies are mountedfor rotation about a common axis and wherein each bucket wheel assemblyincludes means supporting said buckets in spaced array about therotation axis of the bucket wheels, said discharge means including fluidconductors connected to each bucket and extending therefrom generallyradially inwardly towards said rotation axis such that the exit endportions of the fluid conductors are spaced about the rotation axis,said mixer means including means positioned beneath said exit endportions to receive discharge liquid therefrom.
 5. The device accordingto claim 3 wherein the outlet means of said third tank is adapted to beconnected to a user of the proportioned, mixed, liquids, and wherein themeans for creating turbulence within the mixer include a conduitconnected to return unused liquid from said user to said mixer to set upa liquid flow opposing the flow set up in said mixer by the liquidsdischarged from said buckets thereby creating turbulence to ensureproper mixing of the return liquid with the discharged liquids.
 6. Thedevice according to claim 5 wherein the discharge means associated withthe mixer includes a plurality of apertures in a lower portion thereofto permit escape of the mixed liquids from the interior of the mixer. 7.The device according to claim 3 wherein said bucket wheel assemblies aremounted for rotation about a common axis and wherein each bucket wheelassembly includes means supporting said buckets in spaced array aboutthe rotation axis of the bucket wheels, said discharge means includingfluid conductors connected to each bucket and extending therefromgenerally radially inwardly towards said rotation axis such that theexit end portions of the fluid conductors are spaced about the rotationaxis, said mixer means including means positioned beneath said exit endportions to receive discharge liquid therefrom.
 8. Apparatus for mixingand proportioning fluids comprising: a. first and second containers forholding first and second liquid bodies respectively; b. first and secondassemblies supporting first and second sets of spaced bucketsrespectively and arranged to guide said first and second sets of bucketsin first and second paths of travel respectively, said first and secondassemblies arranged such that when the apparatus is in use, a portion ofsaid first path of travel is adapted to pass through the first liquidbody and a portion of the second path is adapted to pass through thesecond liquid body; c. means for driving the first and second sets ofbuckets in their respective paths of travel whereby they successivelyenter and emerge from their respectively associated liquid bodies; d.fill ports in each of said buckets to enable said buckets to fill withsaid liquids during passage of the buckets through said liquids; e.discharge means associated with each of said buckets arrangEd to permitescape of the contents of said buckets after emergence thereof from saidfirst and second liquids, f. mixing means arranged to receive theliquids escaping from said buckets and adapted to mix the first andsecond liquids together, g. the liquid capacity of each bucket of thefirst set being in predetermined relation to the liquid capacity of eachbucket of the second set whereby predetermined proportions of saidliquids are mixed together in said mixing means.
 9. Apparatus accordingto claim 8 wherein said first and second assemblies support the firstand second sets of buckets for movement in circular paths lying inspaced vertical planes.
 10. Apparatus according to claim 9 wherein thebuckets are so arranged on said first and second assemblies thatdischarge of the contents of successive ones of the buckets of the firstset occurs simultaneously with discharge of the contents of successiveones of the buckets of the second set.
 11. Apparatus for mixing andproportioning liquids comprising: a plurality of tanks for containingliquids to be mixed together; each of the tanks having at leastpartially disposed therein an assembly carrying a plurality of buckets,said assemblies being adapted to rotate to cause said buckets tosuccessively enter into and emerge from the liquids contained in theirrespectively associated tanks, means to effect rotation of saidassemblies, means associated with each bucket to permit filling of eachof said buckets during each rotation cycle of each of the assemblies,means associated with each bucket to effect discharge of the contents ofthe buckets at a discharge region, and mixing means adapted to receivethe liquids discharged at the discharge region and adapted to mix theliquids together, the liquid capacities of the buckets of each assemblybeing preselected to permit a desired proportioning of the severalliquids relative to one another.
 12. Apparatus according to claim 11wherein a mixing tank is provided with said mixing means constructed todischarge the mixed liquids into said mixing tank, there being two tanksfor containing liquids to be mixed together disposed in flankingrelation to the mixing tank.
 13. Apparatus according to claim 11 whereineach said assembly comprises means supporting said plurality of bucketsin a circular array for rotation in a vertical plane, each of theassemblies being mounted for rotation about a common axis, there beingequal numbers of buckets on each assembly with said buckets mounted forsubstantially simultaneous discharge of their contents during rotationof said assemblies.
 14. Apparatus according to claim 13 wherein themeans to effect discharge of the buckets includes discharge conduitsassociated with respective ones of said buckets and extending from eachof the latter inwardly towards said common axis to exit end portionsspaced around the latter, such portions generally overlying said mixingmeans.
 15. An apparatus according to claim 14 wherein said mixing meansgenerally includes an elongated trough defining said discharge regionunderlying said rotation axis and disposed to receive liquid dischargingfrom the exit end portions of said conduits, a chamber connected to saidtrough to receive liquids passing from said trough, and means forcreating turbulence within said chamber to create proper mixing of saidliquids.
 16. Apparatus according to claim 15 wherein a mixing tank isprovided to serve as a reservoir for the mixed, proportioned liquids andwherein said chamber has a plurality of apertures in a lower portionthereof to permit outflow of the mixed liquids into the mixing tank,said mixing tank having an outlet opening therein permitting the mixed,proportioned liquids to be supplied to a user.
 17. Apparatus accordingto claim 16 including pump means connected to said outlet opening of themixing tank adapted to supply the mixed liquids to said user, said pumphaving a capacity to supply the liquid at a rate greater than thatdemanded by said user, and a pipe connected to return excess liquid fromsaid user to said mixing tank, said pipe being arranged to direct thereturn flow of excess liquid upwardly into said chamber of the mixingmeans thereby to provide said means for creating turbulence within saidchamber.
 18. Apparatus according to claim 13 including means formaintaining the upper surfaces of the liquids in said tanks atpredetermined levels, said buckets being mounted on their associatedassemblies in such manner as to permit the medial axis of each bucket toassume a true vertical position after the filling means of each bucketrises above the liquid surface during rotation of the assembly on whichsuch bucket is mounted thereby permitting levelling of the contents ofeach bucket.
 19. Apparatus according to claim 18 wherein each saidassembly comprises means supporting said plurality of buckets in acircular array for rotation in a vertical plane, each of the assembliesbeing mounted for rotation about a common axis, there being equalnumbers of buckets on each assembly with said buckets mounted forsubstantially simultaneous discharge of their contents during rotationof said assemblies.
 20. Apparatus according to claim 19 wherein themeans to effect discharge of the buckets includes discharge conduitsassociated with respective ones of said buckets and extending from eachof the latter inwardly towards said common axis to exit end portionsspaced around the latter, such portions generally overlying said mixingmeans.
 21. Apparatus according to claim 20 wherein said mixing meansgenerally includes an elongated trough defining said discharge regionunderlying said rotation axis and disposed to receive liquid dischargingfrom the exit end portions of said conduits, a chamber connected to saidtrough to receive liquids passing from said trough, and means forcreating turbulence within said chamber to create proper mixing of saidliquids.
 22. Apparatus according to claim 21 wherein a mixing tank isprovided to serve as a reservoir for the mixed, proportioned liquids andwherein said chamber has a plurality of apertures in a lower portionthereof to permit outflow of the mixed liquids into the mixing tank,said mixing tank having an outlet opening therein permitting the mixed,proportioned liquids to be supplied to a user.
 23. Apparatus accordingto claim 22 including pump means connected to said outlet opening of themixing tank adapted to supply the mixed liquids to said user, said pumphaving a capacity to supply the liquid at a rate greater than thatdemanded by said user, and a pipe connected to return excess liquid fromsaid user to said mixing tank, said pipe being arranged to direct thereturn flow of excess liquid upwardly into said chamber of the mixingmeans thereby to provide said means for creating turbulence within saidchamber.